Wind power is considered one of the cleanest, most environmentally friendly energy sources presently available, and wind turbines have gained increased attention in this regard. A modern wind turbine typically includes a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture kinetic energy from wind using known airfoil principles and transmit the kinetic energy through rotational energy to turn a main shaft coupling the rotor blades to a gearbox, or if a gearbox is not used, directly to the generator. The generator then converts the mechanical energy to electrical energy that may be deployed to a utility grid.
Modern wind turbines include many bearings to provide rotational movement of its various components. For example, to properly orient the nacelle and the rotor blades relative to the direction of the wind, wind turbines typically include one or more yaw and/or pitch bearings. Such bearings are typically slewing bearings which are rotational ball bearings that support a heavy but slow-turning or slow-oscillating load. Typical yaw and/or pitch bearings include an outer and inner race with a plurality of ball or roller bearings configured between the inner and outer races. As such, yaw bearings permit rotation of the nacelle and are mounted between the tower and the nacelle, whereas pitch bearings permit rotation of the rotor blades and are mounted between the rotatable hub and one of the rotor blades. In addition, wind turbines typically include one or more roller bearings configured with the main shaft to permit rotation thereof. Alternatively, in wind turbines without a main shaft, such roller bearings may be used to permit rotation of the hub with respect to the nacelle.
As wind turbines continue to increase in size, such bearings must similarly increase in size due to increased loading from longer rotor blades. With longer rotor blades also comes increased loads acting on the wind turbine bearings, which are typically very expensive and can be difficult to access and replace. In addition, increasing the size of such bearings and current materials of construction can limit manufacturing capabilities thereof, e.g. in materials and/or providing heat treatment thereto.
Accordingly, an improved bearing that addresses the aforementioned issues would be welcomed in the technology.